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ILLINOIS  LIBRARY 

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BOOKSTACKS 


METEORITES 


BY 


OLIVER  C.  FARRINGTON 
Curator  of  Geology 


FIELD  MUSEUM  OF  NATURAL  HISTORY 

CHICAGO 
1923 


THE  QUINN  CANYON  METEORITE. 
A  TYPICAL  IRON  METEORITE. 


Field  Museum  of  Natural  History 

DEPARTMENT  OF  GEOLOGY 
Chicago,  1923 

Leaflet  Number  4 

Meteorites 

There  are  many  reasons  why  meteorites  are  inter- 
esting objects,  and  chief  among  these  is  the  fact  that 
they  are  our  only  tangible  source  of  knowledge  of  the 
universe  beyond  the  earth.  With  other  heavenly  bod- 
ies we  can  make  only  such  acquaintance  as  can  be 
derived  from  the  rays  of  light  which  come  from  them, 
but  meteorites  can  be  handled,  dissected  and  subjected 
to  the  same  methods  of  analysis  as  terrestrial  sub- 
stances. This  and  other  reasons  have  led  to  the  exer- 
cise of  great  care  and  diligence  among  civilized  peoples 
during  the  last  century  and  a  quarter  at  least,  in  order 
that  as  many  of  these  bodies  as  possible  may  be  pre- 
served and  gathered  in  large  collections  and  their 
various  features  carefully  compared  and  studied. 

In  respect  to  the  number  of  meteorite  falls  repre- 
sented in  one  collection,  Field  Museum  of  Natural 
History  at  present  holds  the  foremost  place.  Of  &20 
meteorite  falls  known  at  the  present  time,  specimens 
of  670  may  be  seen  in  the  Museum  collection.  The 
opportunity  for  the  comprehensive  study  of  these 
bodies  at  this  Museum  is  therefore  unrivalled. 

For  many  of  the  falls  a  fragment  or  section  serves 
as  the  representative.  Many  other  falls  are  repre- 
sented by  complete  individuals  and  some  of  these  are 
the  only  ones  known. 

From  the  number  of  meteorite  falls  occurring  on 
a  measured  portion  of  the  earth's  surface,  it  is  possible 
to  calculate  the  number  which  is  likely  to  occur  annu- 
ally on  the  earth  as  a  whole.    This  has  been  ascertained 

[33] 


2  Field  Museum  of  Natural  History 

to  be  about  900.  But  as  three-fourths  of  the  earth's 
surface  is  covered  with  water,  three-fourths  of  this 
number,  at  least,  will  never  be  found.  Many  of  the 
remainder  which  have  fallen  in  the  desolate  and  unin- 
habited places  of  the  earth  will  never  be  found  because 
of  the  lack  of  finders.  For  these  and  other  reasons, 
the  number  of  meteorites  actually  recovered  over  the 
whole  earth  does  not  average  more  than  three.  Mete- 
orite collections  increase  therefore  slowly.  Not  all 
meteorites  found  in  collections,  however,  were  seen  to 
fall.  The  specific  characters  of  meteorites  are  now 
so  well  known  that  a  mass  can  be  determined  as  a 
meteorite  even  if  its  fall  was  not  observed.  In  fact, 
the  internal  characters  of  a  meteorite  generally  furnish 
more  positive  evidence  of  its  origin  than  the  testi- 
monies of  human  witnesses. 

It  is  not  known  from  what  part  of  the  universe 
meteorites  come  nor  under  what  conditions  they  orig- 
inate. Different  investigators  at  various  times  have 
attempted  to  prove  that  meteorites  are  earth,  moon 
or  sun  substance,  but  the  suggestions  have  not  proved 
satisfactory.  For  several  reasons  meteorites  could  not 
have  come  from  the  earth.  For  instance,  they  differ 
in  composition  in  some  respects  from  any  substances 
found  on  our  planet;  again,  to  have  been  hurled  away 
from  the  earth  they  must  have  received  a  much  greater 
initial  velocity  than  any  terrestrial  eruptive  force  has 
ever  been  known  to  exert.  A  velocity  of  at  least  five 
miles  per  second  must  have  been  given  them  and  this 
is  far  beyond  the  power  of  any  volcano.  Moreover,  a 
large  amount  of  matter  would  need  to  be  flung  into 
space  from  the  earth  in  order  to  furnish  that  which 
reaches  us  as  meteorites,  as  only  a  very  small  propor- 
tion of  that  ejected  could  ever  come  into  the  range  of 
the  earth's  attraction  again.  Similar  reasons  pre- 
clude the  belief  that  meteorites  could  have  come  from 
the  moon. 

[34] 


Meteorites  3 

Objections  to  the  view  that  meteorites  could  have 
come  from  the  sun  are  found  in  the  difficulty  of  con- 
ceiving how  a  globe  in  so  vaporous  and  heated  a  con- 
dition as  the  sun  could  produce  solid  bodies.  Even  if 
the  sun  has  a  solid  core  from  which  compact  or  concrete 
bodies  could  start,  they  would  need  to  pass  through  an 
intensely  heated  atmosphere  before  they  could  arrive 
in  free  space,  and  it  seems  hardly  possible  that  the  solid 
nature  of  small  bodies  could  be  preserved  under  such 
conditions.  Moreover  the  orbits  of  some  meteorites 
make  a  considerable  angle  with  the  plane  of  the  solar 
system  known  as  the  ecliptic,  while  a  body  ejected  from 
the  sun,  in  order  to  reach  the  earth,  must  move  in  this 
plane. 

The  class  of  heavenly  bodies  to  which  the  origin 
of  meteorites  has  been  most  generally  attributed 
within  recent  years  is  that  of  the  comets.  Largely 
through  the  work  of  the  late  Prof.  H.  A.  Newton,  of 
Yale  University,  the  orbits  of  many  of  the  important 
shooting  star  or  meteor  showers  were  found  to  be 
identical  with  those  of  well-known  comets,  these  orbits 
being  in  some  cases  those  of  comets  which  had  disap- 
peared. Thus  the  August  meteors  or  Perseids  were 
found  to  have  the  same  orbit  as  Tuttle's  comet  and 
the  November  or  Leonids  the  same  as  that  of  Tempel's. 
Biela's  comet,  which  disappeared  in  1872,  has  its  place 
in  the  heavens  represented  by  the  so-called  Androm- 
edes  meteor  shower.  Accordingly,  Newton  believed, 
and  the  view  has  been  widely  adopted,  that  meteorites 
are  simply  large  meteors  which  originate,  as  do  the 
small  meteors  or  shooting  stars,  from  the  disintegra- 
tion of  comets. 

If  the  differences  between  the  meteors  which 
produce  meteorites  and  those  which  result  in  star 
showers  so-called  were  only  those  of  size,  this  view 
might  be  accepted,  but  investigation  shows  that 
meteorites   almost   never   fall   during   star   showers. 

[35] 


4  Field  Museum  of  Natural  History 

Only  a  single  case  is  known — that  of  the  Mazapil  iron, 
which  fell  November  27,  1885 — of  a  meteorite  reaching 
the  earth  during  a  star  shower.  So  isolated  a  case 
may  be  accounted  a  pure  coincidence.  Another  objec- 
tion to  the  view  that  meteorites  are  portions  of  comets 
may  be  found  in  the  fact  that  comets  are  not  known 
to  possess  great  bulk  or  even  to  be  composed  of  solid 
matter.  There  are  indications  that  their  substance  is 
largely  or  wholly  gaseous.  In  this  case  their  disinte- 
gration could  not  yield  the  large  masses  of  stone  and 
iron  which  come  to  us  as  meteorites. 

Another  suggested  origin  of  meteorites  has  been 
that  they  are  parts  of  a  shattered  planet  or  planetoid. 
All  evidence  seems  to  indicate  that  meteorites  are 
fragments  of  some  larger  celestial  body  or  bodies. 
How  large  this  body  or  these  bodies  may  have  been 
is  uncertain.  The  rings  of  Saturn  are  known  to  be 
made  up  of  multitudes  of  distinct,  small,  solid  bodies, 
and  it  may  be  that  groups  of  this  nature  are  the  source 
of  meteorites.  The  planetoids,  some  of  which  are 
known  to  be  of  irregular  form,  are  another  possible 
source.  But  the  assumption  that  the  meteorites  which 
reach  the  earth  may  have  originated  by  the  disintegra- 
tion of  larger  bodies  belonging  to  the  solar  system 
requires  for  its  acceptance  (1)  a  satisfactory  sugges- 
tion as  to  the  nature  of  the  forces  by  which  such 
disintegration  could  have  taken  place,  and  (2)  an 
explanation  of  the  inclination  of  the  orbits  of  some 
meteorites  to  the  ecliptic. 

A  possible  solution  of  the  first  difficulty  has  been 
suggested  by  Prof.  Chamberlain  of  the  University  of 
Chicago,  in  the  differential  attraction  exerted  by  the 
passage  of  a  small  body  within  a  certain  distance  of  a 
larger,  dense  one.  The  distance  within  which  disrup- 
tion would  take  place  for  incompressible  fluids  of  the 
same  density  is  given  by  Roche  (Roche's  limit)  as  2.44 
times  the  radius  of  the  large  body.    Since  solid  bodies 

[36] 


Meteorites  5 

possess  some  internal  elasticity,  it  is  probable  that  the 
passage  of  a  larger  body  at  a  somewhat  greater  dis- 
tance than  even  this  would  disrupt  a  smaller  one. 
Here,  then,  is  a  possible  shattering  force.  Another 
would  be  found  in  collisions  of  two  bodies,  but  these 
would  be  less  numerous  than  approaches,  and  these 
collisions  taking  place  between  bodies  moving  at  plan- 
etary velocities  would  be  likely  to  generate  enough 
heat  to  vaporize  their  substance.  The  passage  of  a 
large  body  near  a  small  one  might  also  account  for  the 
peculiar  positions  of  the  orbits  of  some  meteorites  since 
it  would,  in  addition  to  exerting  a  disrupting  effect, 
tend  to  change  the  orbit  of  the  smaller  body.  Such  a 
change  has  often  been  observed  to  be  produced  in  the 
orbit  of  a  comet  by  its  passage  near  a  planet.  Hence 
a  comet  passing  near  a  smaller  body  might  change 
the  orbit  of  the  latter,  drawing  it  out  of  the  ecliptic 
and  giving  it  a  hyperbolic  or  even  a  parabolic  form. 
By  such  means  the  inclination  of  some  meteoritic  orbits 
may  have  been  produced. 

All  known  meteorites  can  for  convenience  be 
grouped  roughly  into  two  classes — stone  and  iron 
meteorites.  In  addition,  an  intermediate  group  known 
as  iron-stone  meteorites  in  which  the  proportions  of 
stone  and  iron  are  about  equal  is  usually  recognized. 

Most  stone  meteorites  have  a  grayish  interior 
covered  with  a  black,  and  more  or  less  shining  crust. 
In  some,  the  mass  of  the  stone  is  so  dark  as  to  be 
wholly  black  or  brownish-black.  Again,  in  others  it 
is  nearly  white.  Further,  the  crust  does  not  always 
differ  in  color  from  the  interior,  especially  in  the  case 
of  brown  or  black  meteorites.  Metallic  grains  scattered 
through  their  mass  usually  form  a  feature  of  stone 
meteorites.  The  coherence  of  the  stone  meteorites 
is  usually  such  that  they  do  not  break  easily  under  the 
blow  of  a  hammer  and  they  take  a  fair  polish.    Some, 

[37] 


6  FieLd  Museum  of  Natural  History 

however,  are  so  soft  that  they  can  be  crumbled  in  the 
fingers. 

The  iron-stone  meteorites  differ  from  the  stone 
variety  chiefly  in  their  abundance  of  metal.  Instead 
of  occurring  as  minute,  scattered  grains  forming  but 
a  small  percentage  of  the  mass  of  the  meteorite,  the 
metal  makes  up  about  half  the  mass  and  is  often  con- 
tinuous. Single  nodules  of  the  metal  often  reach  the 
diameter  of  one  inch  or  more.  Further,  the  metal  may 
be  so  abundant  as  to  form  a  matrix  of  a  sponge-like 
character  in  the  pores  of  which  silicates  are  held. 
Thus  by  gradation  the  iron-stone  meteorites  pass  to 
meteorites  made  up  entirely  of  metal — the  iron 
meteorites. 

The  metal  of  iron  meteorites  is,  when  observed 
immediately  after  falling,  of  a  silver-white  to  grayish- 
white  color  and  usually  malleable.  It  is  composed 
chiefly  of  iron  alloyed  with  from  five  to  twenty-five 
per  cent  of  nickel.  When  found  immediately  after 
falling  also,  iron  meteorites  usually  exhibit  a  blackish 
or  bluish  crust  through  which  the  silvery-appearing 
interior  gleams  here  and  there ;  but  any  long  continued 
exposure  to  the  weather  usually  causes  the  entire  sur- 
face of  such  meteorites  to  become  a  rusty-brown  color. 

A  far  larger  number  of  stone  than  iron  meteorites 
has  been  "observed"  to  fall.  Of  about  350  observed 
falls  only  10  have  been  of  iron  meteorites.  On  the 
other  hand,  among  meteorite  "finds,"  the  iron  meteor- 
ites largely  predominate.  This  is  chiefly  for  the  reason, 
doubtless,  that  the  iron  meteorites  by  their  relatively 
great  weight,  metallic  composition  and  silvery  appear- 
ing interior  attract  the  attention  of  the  ordinary 
observer  much  more  quickly  than  the  stone  meteorites. 
The  latter  show  to  the  casual  observer  no  striking 
differences  from  terrestrial  rocks,  and  are  thus  easily 
overlooked. 

All  meteorites  have  their  surfaces  indented  by 

[38] 


Meteorites  7 

pits  of  a  more  or  less  regular  size  and  shape.  These 
pits  resemble  depressions  such  as  may  be  made  in  a 
lump  of  clay  by  pressing  one's  thumb  into  it  and  hence 
they  are  often  called  "thumb  marks."  Similar  pittings 
are  produced  on  terrestrial  rocks  by  the  action  of  desert 
winds,  and  the  cause  is  the  same  in  both  cases,  namely, 
the  erosive  action  of  the  air,  aided  somewhat  by 
particles  of  stone.  On  iron  meteorites  the  pittings 
are  larger  and  more  irregular  than  on  stone  meteorites 
and  correspond  to  some  extent  to  the  structure  of  the 
iron. 

Meteorites  as  a  rule  have  little  warmth  when 
they  arrive  upon  the  earth.  The  stone  meteorites  are 
almost  always  spoken  of  as  being  "milk  warm"  or 
"barely  warm"  by  those  who  pick  them  up  immediately 
after  their  fall  but  in  some  cases  they  have  been 
intensely  cold.  Thus  one  of  trie  stones  of  the  Colby, 
Wisconsin,  meteorite  fall  which  occurred  at  6 :20  p.  m., 
July  4th,  1917,  although  the  evening  was  one  of  sum- 
mer heat,  was  coated  with  frost  when  it  was  picked 
up  shortly  after  its  fall.  Not  only  are  the  stone 
meteorites  not  hot  themselves  on  falling,  but  the 
ground  where  they  fall  does  not  give  any  indication 
of  being  burned  or  heated.  No  baking  of  the  soil  or 
charring  of  vegetation  can  be  observed.  Where  mete- 
orites have  fallen,  as  has  sometimes  been  the  case,  in 
haystacks,  barns  or  other  places  where  a  little  heat 
might  start  a  fire,  they  have  never  produced  any 
incendiary  effects.  This  lack  of  heat  is  contrary  to 
the  general  belief,  the  common  opinion  being  that 
meteorites  are  intensely  hot  when  they  reach  the  earth. 
This  opinion  is  evidently  based  on  the  brilliant  light 
emitted  by  them  in  their  course  through  the  atmos- 
phere. A  little  consideration  of  the  matter,  however, 
will  convince  one  that  no  heating  should  be  expected. 

1.  The  substance  of  stone  meteorites  is  a  poor 
conductor  of  heat. 

[39] 


8  Field  Museum  of  Natural  History 

2.  The  period  in  which  they  might  acquire  heat 
is  extremely  short,  but  a  few  seconds  at  most. 

3.  Any  portion  of  their  surface  sufficiently  heated 
to  become  in  a  condition  even  approaching  viscosity 
is  immediately  removed  by  the  pressure  of  the  sur- 
rounding air. 

With  the  iron  meteorites  the  case  is  somewhat 
different,  since  they  are  much  better  conductors  of 
heat.  They,  therefore,  generally  possess  considerable 
warmth  when  picked  up  immediately  after  their  fall. 
The  Cabin  Creek  meteorite  is  described  as  being  "as 
warm  as  could  be  handled"  after  being  dug  from  a  hole 
three  feet  deep.  The  Mazapil  meteorite  was  so  warm 
that  it  could  be  "barely  handled"  on  removal.  The 
heat  emitted,  even  in  these  cases,  however,  was  not 
great.  Any  accounts,  therefore,  of  intense  heat  being 
manifested  by  meteorites  can  usually  be  assumed  to  be 
false,  the  observer's  previously  formed  opinion  prob- 
ably coloring  his  testimony  if  his  testimony  is  sincere. 
No  meteorite  fall  has  ever  positively  been  known 
to  have  destroyed  human  life.  Accounts  purporting  to 
describe  such  catastrophies  prove  on  investigation  to 
refer  to  events  so  distant  either  in  time  or  place  that 
they  cannot  be  verified.  Perhaps  the  most  narrow  es- 
cape experienced  was  that  of  three  children  in  Braunau 
at  the  time  of  a  fall  of  a  meteorite  there  in  1847.  This 
meteorite  was  an  iron  weighing  nearly  40  pounds  which 
fell  in  the  room  where  the  children  were  sleeping  but, 
while  it  covered  them  with  debris,  it  caused  them  no  se- 
rious injury.  Other  meteorites  have  fallen  near  human 
beings,  but  have  never  struck  them  so  far  as  credible 
information  goes.  That  personal  injury  or  death  might 
be  caused  by  the  fall  of  a  meteorite  is  entirely  possible, 
it  is  remarkable  that  some  falls,  such  for  instance  as 
the  showers  in  Iowa,  which  occurred  in  comparatively 
thickly  settled  communities,  should  not  have  caused 
serious  injury  to  the  inhabitants. 

[40] 


.1  - 1 


Meteorites  9 

The  oldest  observed  meteorite  fall  of  which  speci- 
mens are  preserved  is  that  which  occurred  at  Ensis- 
heim  in  Alsace,  November  16,  1492.  Between  11  and 
12  a.  m.,  with  a  "loud  crash  of  thunder  and  a  prolonged 
noise  heard  afar  off,"  according  to  the  accounts  which 
have  come  down  to  us  from  that  time,  a  stone  weighing 
260  pounds  fell  in  a  field  at  Ensisheim,  making  a  hole 
five  feet  deep.  It  was  taken  to  the  village  church, 
being  regarded  as  a  miraculous  object.  King  Maxi- 
milian, who  was  then  at  Ensisheim,  had  the  stone 
carried  to  his  castle ;  and  after  breaking  off  two  pieces, 
one  for  the  Duke  Sigismund  of  Austria  and  the  other 
for  himself,  forbade  further  damage  and  ordered  the 
stone  to  be  suspended  in  the  church.  For  a  long  time 
it  hung  in  the  vault  of  the  choir,  but  later  was  removed 
to  the  Rathaus.  A  copy  of  a  drawing  made  at  the 
time,  representing  the  fall  of  the  meteorite,  is  shown 
accompanying. 

Phenomena  of  light  and  sound  similar  to  those 
above  mentioned,  usually  accompany  the  fall  of  a 
meteorite.  These  phenomena  may  be  of  a  startling 
and  even  violent  character  or  they  may  be  scarcely 
perceptible.  Their  nature  and  extent  obviously  vary 
with  the  distance  of  the  observer  from  the  place  of 
passage  of  the  meteor,  or  from  its  place  of  fall,  and 
with  the  time  of  fall.  Occasionally  the  passage  of  a 
meteor  producing  meteorites  may  be  observed  over 
an  area  of  thousands  of  square  miles.  Falls  occurring 
during  the  daytime  may  present  no  visible  phenomena 
of  light,  and  occasionally  no  sound  may  be  heard,  but 
usually  one  or  other  is  observed. 

A  striking  feature  of  some  meteorite  falls  (strik- 
ing both  figuratively  and  literally) ,  is  that  a  large  num- 
ber of  individuals,  sometimes  thousands,  fall  at  one 
time  and  place.  Such  occurrences  are  called  meteoritic 
showers,  and  present  phenomena  of  much  interest. 
These  showers  have  taken  place  on  various  parts  of 

[41] 


10  Field  Museum  of  Natural  History 

the  globe  and  at  various  times  without  any  seeming 
regularity  or  relation.  Three  of  the  largest  showers, 
those  of  Estherville,  Forest  and  Homestead,  took  place 
within  the  boundaries  of  the  state  of  Iowa,  and  three 
others,  Knyahinya,  Mocs,  and  Pultusk,  fell  in  Hungary 
and  the  neighboring  Poland.  The  phenomena  of  violent 
sounds  and  brilliant  light  are  generally  intensified  in 
these  showers,  though  not  always  to  a  marked  degree. 
The  distribution  of  the  meteorites  of  such  a  stone 
shower  is  usually  over  an  elliptical  area,  with  the 
longest  axis  of  the  ellipse  in  the  direction  of  the 
movement  of  the  meteor.  The  greatest  distance  along 
which  the  individuals  of  a  shower  have  been  observed 
to  be  distributed  is  sixteen  miles. 

Besides  showers  of  stones,  showers  of  iron  must 
have  occurred  at  Toluca,  Mexico,  Canyon  Diablo,  Ari- 
zona, and  some  other  localities,  because  large  numbers 
of  iron  meteorites  of  similar  characters  are  found  at 
these  places. 

Most  iron  meteorites  show  on  etching  with  acid 
or  heating,  a  peculiar  structure  which,  so  far  as  is 
known,  is  not  possessed  by  any  terrestrial  substance. 
This  structure  is  due  to  three  alloys  of  nickel  and  iron 
which  have  a  crystalline  arrangement  according  to  the 
planes  of  an  octahedron.  On  etching  a  polished  section 
of  such  a  meteorite  this  structure  is  displayed  in  the 
form  of  a  network  of  intersecting  bands  known  as 
Widmanstatten  or  Widmanstattian  figures,  so  named 
after  their  discoverer,  Alois  von  Widmanstatten  of 
Vienna,  who  first  observed  them  in  1808.  These  figures 
are  constant  throughout  a  single  meteorite,  but  differ 
in  separate  falls.  The  bands  vary  in  widths  from  fine 
to  coarse,  becoming  narrower  as  the  percentage  of 
nickel  increases.  Iron  meteorites  having  less  than  7 
per  cent  of  nickel  do  not  exhibit  these  figures.  They 
show  on  etching  only  a  network  of  minute  lines,  which 
are  arranged  in  three  directions  at  right  angles  to  each 

[42] 


Meteorites  11 

other,  or  in  other  words,  according  to  the  lines  of  a 
cube.  Other  iron  meteorites  show  no  markings  upon 
etching.  Their  structure  may  have  been  destroyed  by 
pre-terrestrial  heating  or  their  content  of  nickel  may 
have  been  too  high  for  crystallization. 

A  feature  peculiar  to  about  nine-tenths  of  all  stone 
meteorites  is  that  of  being  largely  made  up  of  rounded 
grains  or  spherules.  These  spherules,  known  as 
chondri  or  chondrules,  differ  from  any  structures  found 
in  terrestrial  rocks.  They  consist  of  the  same  minerals 
which  make  up  the  substance  of  the  meteorite,  usually 
in  granular  or  acicular  imperfectly  crystallized  forms. 
They  may  be  a  peculiar  mode  of  crystallization  or  may 
owe  their  spherical  form  to  trituration  such  as  may 
occur  in  a  meteoric  swarm  when  its  component  parts 
beat  against  each  other. 

Several  compounds  occur  in  meteorites  which  do 
not  occur  terrestrially.  The  most  important  of  these 
are  schreibersite  and  cohenite,  respectively  a  phosphide 
and  carbide  of  iron  and  nickel.  A  sulphide  of  calcium, 
oldhamite,  not  found  terrestrially,  also  occurs  in  mete- 
orites. The  occurrence  of  such  compounds  as  well  as 
the  large  amount  of  unoxidized  iron  in  meteorites 
indicates  an  absence  of  oxygen  in  the  conditions  under 
which  they  were  formed. 

The  stone  meteorites  are  chiefly  composed  of  sil- 
icates of  magnesium,  in  the  form  of  the  minerals  known 
as  enstatite  and  chrysolite,  and  the  iron  meteorites 
consist  chiefly  of  iron  with  from  5  to  20  per  cent  of 
nickel.  Some  cobalt  and  copper  usually  accompany  the 
nickel  and,  in  some  cases,  platinum. 

The  Museum  meteorite  collection  is  exhibited  in 
twelve  cases  in  Hall  34  on  the  second  floor  of  the  build- 
ing and  in  one  case  in  Stanley  Field  Hall  on  the  main 
floor. 

Oliver  C.  Farrington. 


[43] 


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